This invention relates generally to thermostats having illuminated keypads and displays and more particularly to thermostats having keypads and displays illuminated by electroluminescent elements.
Thermostats are generally attached to walls inside buildings for controlling heating and cooling systems of the buildings. Some thermostats have displays and keypads. The displays are adapted to display information, such as temperature of the room, thermostat settings, time of day, and programming information. The keypad enables a user to input signals to the thermostat to change thermostat settings or to alter the display. Occasionally, the user may desire to change thermostat settings at night. In order to see the keypad, the user must turn on a light in the room, which may be undesirable if another person is sleeping in the room at the time.
The present invention overcomes the disadvantages of the prior art thermostats. Among the advantages of the present invention may be noted the provision of a thermostat having an illuminated display and an illuminated keypad.
Generally, a thermostat of the present invention comprises a circuit system for controlling the thermostat, a display, a keypad, and at least one electroluminescent element. The display is operatively connected to the circuit system for displaying information concerning the thermostat. The keypad has at least one key adapted to be pressed by a user. The at least one key is operatively connected to the circuit system in a manner to enable the user to input at least one signal to the circuit system by pressing the key. The at least one electroluminescent element is operatively connected to the circuit system and has a first electroluminescent section and a second electroluminescent section. The first electroluminescent section is adjacent the keypad and the second electroluminescent section is adjacent the display. The first electroluminescent section and the keypad are adapted so that the first electroluminescent section illuminates the keypad. The second electroluminescent section and the display are adapted so that the second electroluminescent section illuminates the display.
In another aspect of the present invention, a thermostat of the present invention comprises a circuit board, an electroluminescent element on the circuit board, a keypad member and a display. The circuit board has a plurality of actuable elements thereon. The electroluminescent element has first and second sections, the first section having a plurality of openings therein aligned with the actuable elements on the circuit board. The keypad member overlies the first section of the electroluminescent element. The keypad member has at least one relatively thick portion forming a key aligned with one of the openings in the electroluminescent element. Each key is surrounded by a relatively thin, flexible portion to allow the key to be depressed to actuate an actuable element on the circuit board that is aligned with the same opening in the first section of the electroluminescent element with which the key is aligned. The display overlies the second portion of the electroluminescent element. The electroluminescent element is adapted to illuminate the keypad member and the display.
In another aspect of the present invention, an illuminated thermostat comprises a circuit system for controlling the thermostat, a display, and a keypad. The display is electrically coupled to the circuit system for displaying information concerning the thermostat. The keypad has at least one key adapted to be pressed by a user. The at least one key is operatively connected to the circuit system in a manner to enable the user to input at least one signal to the circuit system by pressing the key. The thermostat further comprises means for illuminating the display and keypad. The illuminating means may comprise one or more electroluminescent elements for illuminating the display and keypad. Alternatively, the illuminating means may comprise an electroluminescent element for illuminating the keypad and some other illuminating mechanism (e.g., a Light Emitting Diode (LED)) for illuminating the display.
Other objects and features will be in part apparent and in part pointed out hereinafter.